OK, so the BEST part of the American Idol season 8 finale was David Cook's performance of Permanent.
A close second was Kara DioGuardi laying the smackdown (in a manner of speaking) on Bikini Girl, Katrina Darrell. Anyone who watched the auditions will remember her. She came to the auditions in a bikini and high heels, sang a Mariah Carey song (which you simply should not do unless you are an EXTREMELY talented vocalist) and proceded to be rude to Kara when she pointed out that the song was a big song that she just "didn't have the chops to sing". She then criticized Kara as though Kara couldn't sing any better, and of course, acted like the women just disliked her because she is soooooooooooo gorgeous. She was a total snot during the Hollywood round and her own team hated her. She didn't make it through,thankfully.
Anyway, during the season 8 finale, she was totally set up and Kara got her revenge.